The ratio between the size of the image in pixels and its physical size when printed on paper. select one: a. selection b. compression c. vector d. resolution

Can someone help me with this math question

Evaluate 6+\dfrac4a+\dfrac b36+ a 4 ​ + 3 b ​ 6, plus, start fraction, 4, divided by, a, end fraction, plus, start fraction, b, divided by, 3, end fraction when a=4a=4a, equals, 4 and b=3b=3b, equals, 3.

c. find the sum of the following using the unit indicated.1) 4m + 45 cm + 48dm + 465 kmmeters2) 4 kg + 5000 g + 55 lbs.kg3) 5hrs + 30 min. + 10,800 sec.hours4) 7 cm2 +1.256 dm2 +0.002 m2cm25) 4.1 l + 4.2 dm + 90 cl + 65000 cm? =6) 16.9 l + 1200cl + 4080 l​